package Tools;

import java.util.Random;

public class MyTool {
    public static String code(){
        String res = "";
        char[] str ={'1','2','3','4','5','6','7','8','9','0','a','b','c','A','B','C',};
        Random random = new Random();

        for (int i = 0; i < 4; i++) {
            int anInt = random.nextInt(16);
            res+=str [anInt];
        }
        return res;
    }
}
